We are using these in place of the Extra Aggressive erasers that we can no longer get. the grit is not as rough but they do a good job at a fair price.

Aggressive eraser:

This is an eraser that looks like a pencil. The eraser is of a coarse nature that removes pencil, ink, and lightly applied paints. It is an aggressive, sharpen-able, wood encased, pencil-type eraser. These (and similar) are among our most heavily used tools outside of the airbrush itself.